Well now that we are talking directly to each other..Norm.

I will not bore you with my complete history in 3D CAD, but it started in 1982 with Computervision (3D wireframe with some surfacing) then CADKEY in 1985, which I was instrumental in bringing PC based 3D modeling to Boeing. I became a CADKEY VAR.

In the beginning I was incredibly excited about what you are doing now. All that manufacturing needs is the model and some qualifying dimensions. But when I started selling CAM software I began communicating with Job shops (independent machine shops). Soon I was providing them models to do CNC programming. It started with 3D wireframe models, and then surfaced models (some for stl), then of course, complete solid models generated from paper or Acad drawings. These Job shops are not privy to the complete assembly, many times for confidential reasons, mostly because it is not their job to review the design. It is here where the minimum data concept falls apart. The Job shop now gets this kind of data and now I am hired to do complete detail drawings so they can inspect the parts. Believe me I have gone through this process with hundreds of parts that if they did a drawing many of the parts would have been done totally different.

There may be a standard that will allow this to be done automatically. But that is not the point I am trying to get across to you. The drawing delivers a complete description of the part. You don’t need special software to view it, evaluate it, check it, etc. You have one easy to read document with all the info of that part or assembly. Drawings from solids are not that difficult, in fact they are quite easy by a skilled drafter. No more than a few hours for rather complex parts. But not only does the drawing deliver the complete description it also allows the design engineer, designer, drafter, checker, manufacturing engineer, planning, engineering groups to review the design. It is a hard copy of all the information in one easy document. Now of course we haven’t even talked about revisions. As for errors, since you do have both the solid model and a drawing, you have a double check on the part.

I have talked to one of my customers and associates that is a drafting instructor at a local community college. I asked him can we do away with drafting. He believes that knowing how to create and read drawings is the basis for good design communication. That is a good question for you, Norm. Do we need to train drafters?? Do we need drafting programs?? As you know drafting is taught for only one quarter in an engineering degree, I have taught many engineers how to draw while on contract at Martin Marietta. They had no idea what a datum was. So how do we teach good design, are you saying the concept that has produced programs like the space shuttle, 707, 747, C5A, etc is now archaic. Just a few dimensions on a solid model are all that is required.

I see you have a vested interest in pushing this concept. It may work in a system that has total control from design to part release. But from my experience, working with smaller Job shops that really don’t have the expert personnel to do this extra work, we will always need the complete engineering drawing. I believe that the short time spent doing a complete detail drawing on the front end, and providing manufacturing with both the drawing and solid model is the complete communication solution to provide manufacturing with necessary data.